Lots of great feedback here, and I appreciate the thoughtful concern from all.
We are going to have to research the logistics of her pensioner's plan, which begins in Australia next year as she will have been a resident for ten years at that point.
Being a Rhodesian is a unique circumstance because the home you're tied to, doesn't really exist anymore. My MIL escaped to South Africa, married and had a son there, and ultimately ended up relocating again when she remarried. The family she keeps in touch with is almost entirely in other countries already. We definitely have her best interests at heart and leaving her in Australia without loved ones, is a concern great enough to warrant a financial plan to get her here. Perhaps she will even be able to maintain her pensioner's abroad, I'm unsure of the stipulations of that, but rest assured I will be looking into it.
We aren't millionaires but we want to include this in our 5 and 10 year plan if we can. Understanding end of life care and its demands as I just lost my father to an eleven year battle with cancer, I absolutely want to remain pragmatic about this. So, seeing as most of this advice is well-meaning yet anecdotal, I guess I'll have to take some time to delve into law specific to Iowa, as well as Australia.
My husband is her only child, and I know she will want to be with us. She confirmed it again last night. Just need to work out how to make it happen, realistically.